This experiment is created to emphasis that the velocity, or rate of water flow in a stream affects the size of the particles found in that stream. This is a depiction of the Enduring Understanding Earth is a complex system of interacting rocks, water, energy, air and life. It attempts to give the students ways to find answers to the Essential Question, "How can we use our understandings of change and systems to predict future changes?"
Objectives:
Students will be able to identify the patterns of stream flow.
Students will be able to classify sediments as to their particulates (clay, sand, silt and gravel/boulder).
Students will be able to measure in increments of 1 mm
Students will understand the system of interacting particulates, water and energy in a stream.
Students will be able to apply their knowledge of stream flow to make decisions about future events at the stream
Time Line:
This unit includes five activities. Each activity was created to fill one class period of approximately 40 minutes.
Worksheets for each activity can be found in the student activity page of this website.
Materials needed:
The following materials will be needed to implement this lesson:
If you work in the best of all possible worlds
For each group
If you work where we do
One set up to share:
1. Long shallow container, at least 5 feet long ( you can use plastic under the bed storage units like the ones sold in Target or Wal-Mart)
2. Variable speed fish tank pump
3. Extension cord (to plug in fish pump)
4. Various soil samples brought in by students.
5. Copy of the Hjulstrom Diagram
6. Ruler measures in mm (one for each student
7. Student worksheet
1. Long shallow container, at least 5 feet long ( you can use plastic under the bed storage units like the ones sold in Target or Wal-Mart)
2. Variable speed fish tank pump
3. Extension cord (to plug in fish pump)
4. Various soil samples brought in by students.
5. Copy of the Hjulstrom Diagram (one for each group)
6. Ruler measured in mm (one for each student)
7. Student worksheet
Preparing For The Class:
You will need to set up the tank in advance. Fill the storage container with water. Submerge the fish tank pump at one end of the container. The pump will pull water in one side and push it out the other. Make sure you can see a flow of water in your tank. You might want to test the high and low setting to make sure you can see a difference in the water flow.
Background Information:
Teacher Guide – Science content
Rivers are channels that meander through Earth’s surface. As rivers course through the landscape, they shape it by cutting and then depositing material from its channel. The cuts along the bank are referred to as the cut bank. Where debris is deposited along the channel it is referred to as the point bar. Within the channel there are various depths and velocities of water flow. To determine the various depths of a river, the channel is divided into at least 20 or more cross sections; within each section the depth is measured. The velocities of a river change with depth and volume of water within the channel; more volume, greater velocity and greater depth, less velocity due to frictional force along bottom of channel.
The sketch shows the outline of a channel and how the cuts and fills can change the shape and flow of water over time. The solid lines represent present day course of water. The dashed lines represent the anticipated future flow of water.
Change is constant and several of the Earth’s systems are always interacting, in this case water and rocky material. As a result the natural landscape will alter due to these interactions. In the case of a channel, gravity pulls the water down stream and the cut and movement of material will widen the channel (at cut banks) and fill-in (point bars). Knowing this information is useful when planning for future land use and resources.
The following sites are recommended for comprehensive and concise background for teachers and/or students.
http://sos.noaa.gov/datasets/Land/paleo.html, developed by National Oceanic and Atmospheric Administration
These animations are timed in slow motion, giving the viewer a clearer picture of plate movement and the subsequent transformation of landmass.
http://tapestry.usgs.gov/Default.html, developed by the U.S. Geological Survey
Specifically under Description of Features, selecting #14, will offer a description of the Fall line where the higher elevations of the Appalachians abut the lower elevations of the Coastal Plain.
Under Color Legend, select the Cambrian period within Paleozoic era to follow the links to a description of the ages of rocks in the Appalachians. Note the interweaving of the various colors that represent the metamorphic nature of rocks within this area.
Students will be asked to bring in samples of soil from their homes. Each student will be required to bring in a baggie worth of soil. It is important not to say much more than that, so you can analyze their knowledge of what soil is. Students will broken into groups. In their groups they are asked to dump their soil samples together and sort the new sample as to its particle size. The four sizes they will be sorting areboulder/cobble (anything bigger than 15 mm) gravel (14 mm - 3 mm) Sand (2 mm- 1 mm) silt (less than 1 mm). The actual measures are boulder/cobble more than 15 mm, gravel 2-15mm, sand .06 – 2 mm, silt .004 - .06 mm, and clay less than .004 mm. We believe the concept will be solidified by allowing students to use the clearer cut points and still get the same understanding of the concept. This is also a good place to reinforce their understanding and practice of metric units.
By analyzing soil from their own environment students will start to develop an understanding of Earth as a complex system of interacting rocks, water, energy, air and life.
A PDF of this worksheet can be found on the student activity page.
Particle Size Worksheet Grading Rubric
0
1
2
3
4
Brought in soil sample
Didn’t bring in sample
N/A
N/A
N/A
Brought in sample
Identified particles
refuse to participate
Particles not sorted properly
Less than half particles sorted properly
Most particles sorted properly
All correct
Answered questions
No paper handed in
Answers on paper do not correspond to sorting
Some answers correlate to results
Answers make sense
Part 2 – Moving Particles Through Water After sorting their soils, students are asked to remix their samples. This can be done by putting all samples into a large zip-lock bag and shaking. are then asked to take a handful of their mixed samples and drop them into the stream created by the pump both at high velocity and low velocity. They are asked to pay attention to the particles and record what happens to each kind of particle. It is important to have the pump off as the students put their soil in the stream. Just dropping particles will have the larger particles falling first and smaller ones being taken away. In a real streambed the particles are already on the bottom or side of the stream and are picked up as the water flows by. As the students are experimenting you might want to circulate and focus their attention by asking the following questions:
What kind of particles did the faster water push best?
What kind of particles did the slower water push best?
Was there any difference between the velocity of the water and the particles that were pushed?
By observing the interaction between particulates (their soil samples) and water students are adding a layer to their understanding of Earth as a complex system of interacting rocks, water, energy, air and life.
A PDF of this worksheet can be found on the Student Activity Page.
Stream Flow grading Rubric
4
3
2
1
Drawing - details
All assigned details have been added. The details are clear and easy to identify.
Almost all assigned details (at least 85%) have been added. The details are clear and easy to identify.
Almost all assigned details (at least 85%) have been added. A few details are difficult to identify.
Fewer than 85% of the assigned details are present OR most details are difficult to identify.
Accuracy
95% or more of the assigned structures are drawn accurately and are recognizable. All assigned structures are labeled accurately.
94-85% of the assigned structures are drawn accurately and are recognizable. All assigned structures are labeled accurately.
94-85% of the assigned structures are drawn accurately and are recognizable. 94-85% of the assigned structures are labeled accurately.
Less than 85% of the assigned structures are drawn AND/OR labeled accurately.
Knowledge Gained
Identified 3 similarities and 3 accurately
Identified 2 similarities and 2 differences accurately
Identified 1 similarities and 1 differences accurately
Answers do not make sense
Part 3 Introducing the Hjulstrom Diagram:
The Hjulstrom curve is a graph that shows the relationship between the velocity of a river and the particle sizes that may be transported. It shows the velocity needed to pick up material of a certain size (velocity needed for erosion to take place), and the settling velocity when deposition will occur. Though the iterative process of science it has been shown that particle size and stream velocity have a specific relationship. They know that they can use this relationship to determine the velocity of a stream just by studying its particle size. Because of this, even if a stream bed is dry, you can use the size of the particles that remain to determine the velocity of the stream that once ran through it.
By allowing students to apply what they know to what scientists know they are adding another layer to their understanding of Earth is a complex system of interacting rocks, water, energy, air and life; and how those changes are predictable.
Students are given a worksheet with the Hjulstrom Diagram and asked to analyze it.
A PDF of this worksheet can be found on the Student Activity Page.
Hjulstrom Diagram Worksheet Grading Rubric
Knowledge
0
2
3
4
Knowledge
Answers do not make sense
Identified 1 similarity and one difference accurately
Identified 2 similarities and differences accurately
Identified 3 similarities and differences accurately
Part 4 - Data:
Your students will use this data to apply their new knowledge of cut banks, point bars stream velocities and sediment distribution.
Two teachers went to Wilson Run creek with a scientific instrument known as a flow meter. They used this instrument to take measurements of the velocity of the creek. They found that water flowed faster on one side of Wilson Creek than it did on the other. They took samples of sediments from each side. They measured the size of the particles and compared them to the Hjulstrom Diagram.
If the Hjlstrom Diagram is correct, which set of sediments came from the slower side of the stream (known as the point bar) and faster side (known as a cut bank)? Field Analysis of Data Collected at Brandywine State Park Wilson Run Creek on Wednesday, July 14, 2010.
A PDF of this worksheet can be found on the Student Activity Page.
Data analysis Worksheet Grading Rubric
Knowledge
0
2
3
4
Knowledge
Answers do not make sense
Answers are reversed
Identified correctly but gave no reason for their answers
Identified correctly and gave good reasons for their answer
Notes:
Cross sections are measured from cut bank (0) to point bar (14 feet). The measurements in the creek channel are at 2 feet increments, of which these have been converted to metric as noted above.
Signs in front of values are interrupted as direction only; negative values are flow down stream away from the flow meter, while positive values are toward the meter as upstream flow.
Analysis: Water flow at the fill bar, 2-foot vertical cut, was slowest due to water bouncing off grass, in an upstream direction, and slowing flow. On the cut bank water was slowest at the 4-foot mark versus the 2-foot mark. This may be due to a slight increase in the water’s flow as it hit the man-made wall, initially increasing velocity as water struck the wall. The highest rates of flow were at the 8 foot and 10 foot vertical cuts. Flow velocity was greatest at these points because water was channeling toward the fill bank and there was no obstruction to interfere with flow, as at vertical cut 12.
Data analysis Worksheet Grading Rubric
Knowledge
0
2
3
4
Knowledge
Answers do not make sense
Answers are reversed
Identified correctly but gave no reason for their answers
Identified correctly and gave good reasons for their answers
Student :
In the last activity students are asked to draw a picture of what they think the stream looks like both at the time of the data collection and 10 years into the future. Students draw a picture of what they think the stream looks like. They then change papers and have their partner analyze their drawings. A class discussion of different features will create a group picture of what they think the stream should look like. Students then go back to the picture page to see how closely their drawing represent the actual pictures on the website.
Students are asked to take their new knowledge of stream flow and redraw their pictures to depict the stream as it will look 10 years from now. Teachers can used these pictures and the responses underneath to assess how well their students understand the concept of stream flow and erosion.
By comparing what they thought the stream looked like to actual pictures on the Brandywine Website Students are able to apply what they have found out about how water and particulates interact. These observations will give them the tools they need to use their understandings of change and systems to predict future changes.
Background information
Student Activity Pages
Brandywine Virtual Field Trip
National Science Standards Addressed
Teacher Guide
Brandywine State Park
Teacher Guide
Purpose:
This experiment is created to emphasis that the velocity, or rate of water flow in a stream affects the size of the particles found in that stream. This is a depiction of the Enduring Understanding Earth is a complex system of interacting rocks, water, energy, air and life. It attempts to give the students ways to find answers to the Essential Question, "How can we use our understandings of change and systems to predict future changes?"Objectives:
Time Line:
This unit includes five activities. Each activity was created to fill one class period of approximately 40 minutes.Worksheets for each activity can be found in the student activity page of this website.
Materials needed:
The following materials will be needed to implement this lesson:For each group
One set up to share:
2. Variable speed fish tank pump
3. Extension cord (to plug in fish pump)
4. Various soil samples brought in by students.
5. Copy of the Hjulstrom Diagram
6. Ruler measures in mm (one for each student
7. Student worksheet
2. Variable speed fish tank pump
3. Extension cord (to plug in fish pump)
4. Various soil samples brought in by students.
5. Copy of the Hjulstrom Diagram (one for each group)
6. Ruler measured in mm (one for each student)
7. Student worksheet
Preparing For The Class:
You will need to set up the tank in advance. Fill the storage container with water. Submerge the fish tank pump at one end of the container. The pump will pull water in one side and push it out the other. Make sure you can see a flow of water in your tank. You might want to test the high and low setting to make sure you can see a difference in the water flow.Background Information:
Teacher Guide – Science contentRivers are channels that meander through Earth’s surface. As rivers course through the landscape, they shape it by cutting and then depositing material from its channel. The cuts along the bank are referred to as the cut bank. Where debris is deposited along the channel it is referred to as the point bar. Within the channel there are various depths and velocities of water flow. To determine the various depths of a river, the channel is divided into at least 20 or more cross sections; within each section the depth is measured. The velocities of a river change with depth and volume of water within the channel; more volume, greater velocity and greater depth, less velocity due to frictional force along bottom of channel.
The sketch shows the outline of a channel and how the cuts and fills can change the shape and flow of water over time. The solid lines represent present day course of water. The dashed lines represent the anticipated future flow of water.
Change is constant and several of the Earth’s systems are always interacting, in this case water and rocky material. As a result the natural landscape will alter due to these interactions. In the case of a channel, gravity pulls the water down stream and the cut and movement of material will widen the channel (at cut banks) and fill-in (point bars). Knowing this information is useful when planning for future land use and resources.
The following sites are recommended for comprehensive and concise background for teachers and/or students.
Plate Tectonics
- http://pubs.usgs.gov/publications/text/dynamic.html, developed by the U.S. Geologic Survey
- http://sos.noaa.gov/datasets/Land/paleo.html, developed by National Oceanic and Atmospheric Administration
PiedmontsThis online text provides information in an easy to read format, particularly for high school students.
These animations are timed in slow motion, giving the viewer a clearer picture of plate movement and the subsequent transformation of landmass.
- http://www.priweb.org/ed/TFGuide/NE/geo_history/ne_geohist_main2.htm.
Topography of the United StatesSelect Exotic Terraces for a .pdf document titled Mountain Building Part IV: The Formation of Pangaea and the Appalachian Mountains.
- http://tapestry.usgs.gov/Default.html, developed by the U.S. Geological Survey
Rocks of the NortheastSpecifically under Description of Features, selecting #14, will offer a description of the Fall line where the higher elevations of the Appalachians abut the lower elevations of the Coastal Plain.
Under Color Legend, select the Cambrian period within Paleozoic era to follow the links to a description of the ages of rocks in the Appalachians. Note the interweaving of the various colors that represent the metamorphic nature of rocks within this area.
- http://www.priweb.org/ed/TFGuide/NE/rocks/ne_rocks_main.htm, developed by The Paleontological Research Institution
Nature of StreamsSelect Appalachian & Piedmont for a .pdf document about the rocks of the region.http://geology.com/rocks/, catalogs a variety of rocks and minerals and includes plethora of information on earth science
Part 1 – Analyzing Soil Samples
Students will be asked to bring in samples of soil from their homes. Each student will be required to bring in a baggie worth of soil. It is important not to say much more than that, so you can analyze their knowledge of what soil is. Students will broken into groups. In their groups they are asked to dump their soil samples together and sort the new sample as to its particle size. The four sizes they will be sorting are
By analyzing soil from their own environment students will start to develop an understanding of Earth as a complex system of interacting rocks, water, energy, air and life.
A PDF of this worksheet can be found on the student activity page.
Part 2 – Moving Particles Through Water
After sorting their soils, students are asked to remix their samples. This can be done by putting all samples into a large zip-lock bag and shaking.
By observing the interaction between particulates (their soil samples) and water students are adding a layer to their understanding of Earth as a complex system of interacting rocks, water, energy, air and life.
A PDF of this worksheet can be found on the Student Activity Page.
Part 3 Introducing the Hjulstrom Diagram:
The Hjulstrom curve is a graph that shows the relationship between the velocity of a river and the particle sizes that may be transported. It shows the velocity needed to pick up material of a certain size (velocity needed for erosion to take place), and the settling velocity when deposition will occur. Though the iterative process of science it has been shown that particle size and stream velocity have a specific relationship. They know that they can use this relationship to determine the velocity of a stream just by studying its particle size. Because of this, even if a stream bed is dry, you can use the size of the particles that remain to determine the velocity of the stream that once ran through it.
By allowing students to apply what they know to what scientists know they are adding another layer to their understanding of Earth is a complex system of interacting rocks, water, energy, air and life; and how those changes are predictable.
Students are given a worksheet with the Hjulstrom Diagram and asked to analyze it.
A PDF of this worksheet can be found on the Student Activity Page.
Part 4 - Data:
Your students will use this data to apply their new knowledge of cut banks, point bars stream velocities and sediment distribution.Two teachers went to Wilson Run creek with a scientific instrument known as a flow meter. They used this instrument to take measurements of the velocity of the creek. They found that water flowed faster on one side of Wilson Creek than it did on the other. They took samples of sediments from each side. They measured the size of the particles and compared them to the Hjulstrom Diagram.
If the Hjlstrom Diagram is correct, which set of sediments came from the slower side of the stream (known as the point bar) and faster side (known as a cut bank)?
Field Analysis of Data Collected at Brandywine State Park Wilson Run Creek on Wednesday, July 14, 2010.
A PDF of this worksheet can be found on the Student Activity Page.
- Cross sections are measured from cut bank (0) to point bar (14 feet). The measurements in the creek channel are at 2 feet increments, of which these have been converted to metric as noted above.
- Signs in front of values are interrupted as direction only; negative values are flow down stream away from the flow meter, while positive values are toward the meter as upstream flow.
Analysis:Water flow at the fill bar, 2-foot vertical cut, was slowest due to water bouncing off grass, in an upstream direction, and slowing flow. On the cut bank water was slowest at the 4-foot mark versus the 2-foot mark. This may be due to a slight increase in the water’s flow as it hit the man-made wall, initially increasing velocity as water struck the wall. The highest rates of flow were at the 8 foot and 10 foot vertical cuts. Flow velocity was greatest at these points because water was channeling toward the fill bank and there was no obstruction to interfere with flow, as at vertical cut 12.
Student
:
In the last activity students are asked to draw a picture of what they think the stream looks like both at the time of the data collection and 10 years into the future. Students draw a picture of what they think the stream looks like. They then change papers and have their partner analyze their drawings. A class discussion of different features will create a group picture of what they think the stream should look like. Students then go back to the picture page to see how closely their drawing represent the actual pictures on the website.Students are asked to take their new knowledge of stream flow and redraw their pictures to depict the stream as it will look 10 years from now. Teachers can used these pictures and the responses underneath to assess how well their students understand the concept of stream flow and erosion.
By comparing what they thought the stream looked like to actual pictures on the Brandywine Website Students are able to apply what they have found out about how water and particulates interact. These observations will give them the tools they need to use their understandings of change and systems to predict future changes.